Commercially insured patients who use the life-saving epinephrine auto-injector known as ‘EpiPen’ have experienced skyrocketing out-of-pocket costs since 2007, according to research published March 27 in JAMA Internal Medicine.

Researchers from the University of Chicago Medicine say aggressive drug company pricing, combined with insurance coverage policies that fail to adequately protect patients financially, has caused a nearly 124 percent increase in the amount of money people spend each year on EpiPens. The increase in out-of-pocket spending from $33.80 to $75.50 occurred despite the fact that the rate of prescription fills for EpiPen barely changed during that period. Commercially insured patients account for 70 percent of patients who use EpiPen. The researchers analyzed data from 191.2 million enrollees in the 2007-2014 Truven MarketScan Commercial Claims and Encounters database. MarketScan contains data from individuals aged 0-64 who receive private insurance from more than 100 employers in all 50 states.

The researchers speculated the price surge could cause some patients to skip buying the product.

“The major concern is that these increases may lead patients to forego filling EpiPen prescriptions due to cost, since having an EpiPen can mean the difference between life and death when serious allergic reactions occur,” said Kao-Ping Chua, MD, PhD, lead author on the study and assistant professor of pediatrics and public health sciences at the University of Chicago Medicine. “I have met families in the pediatric emergency department who have told me that cost prevents them from replacing their child’s expired EpiPen every year. I also know a patient with a history of serious allergic reactions who only gets an EpiPen when her relative fills a prescription for an EpiPen two-pack and shares the extra one with her.”

EpiPen is the most widely used epinephrine auto-injector. Many patients need to carry the devices around with them to prevent life-threatening complications from a severe allergy attack. After pharmaceutical company Mylan obtained the right to EpiPen in 2007, its list price increased from $94 to $609.

Last December, the company released a $300 generic version—partly in response to patient outrage over rising costs.

“Mylan’s introduction of a generic alternative is not a real solution to the affordability problem. Many patients will still have substantial out-of-pocket spending for generic EpiPen because of the cost-sharing their insurance plan requires,” said Dr. Chua.

“The bottom line is that drug manufacturers and insurers should not force individuals and families to pay high amounts out-of-pocket for life-saving drugs like EpiPen. These pricing practices erode patient and public health. Patients, physicians, and policymakers should advocate for fair pricing and adequate insurance coverage of life-saving emergency drugs,” said the study’s senior author Rena Conti, PhD, associate professor in the departments of Pediatrics and Public Health Sciences.